Design, fabrication and mechanical properties of 3D printed polylactic acid scaffolds for bone tissue engineering

Abstract

Polylactic acid scaffolds produced by 3D printing is a promising strategy for bone tissue engineering. The aims of this study can be divided into two distinct phases. The former was to design, optimize and print scaffolds with a FDM desktop 3D printer with different levels of porosity for BTE applications. The latter was to research the mechanical properties of the resulting polylactic acid scaffolds and to compare it to the strength of cortical and trabecular bones. A commercial fused deposition modeling desktop 3D printer was used to print the scaffolds. They were then printed into scaffolds and compressed for their mechanical properties. Three prototype parts, denoted as straight stacked beams, porous sodalite crystals and porous hexagonal prisms, were designed with three different porosities: 25%, 50% and 70%. Scaffolds with wall thicknesses as low as 300 μm were printed and their mechanical properties measured. The compressive strength of printed scaffolds ranged from 2.23 MPa to 43.23 MPa depending on their design and porosity level. This range is satisfactory in comparison to trabecular bone (1.5 MPa to 45 MPa), but unacceptable when compared to cortical bone (90 MPa to 209 MPa). The designs, production method and materials provide appropriate porosity and mechanical properties to allow trabecular bone tissue regeneration and could serve as a cost-effective way of creating regenerative implants for damaged or defective trabecular bone.